The present invention relates to a detent arrangement for locking and, in the case of an overload, unlocking the coupling pin of an overload element, particularly in an overload clutch, with the front end of a coupling pin that is displaceably arranged in one clutch half being in form-locking engagement with the other clutch half. In the case of an overload, this engagement is released by the axial displacement of the coupling pin which causes it to move away from the other clutch half. The rear end of the coupling pin is disposed in a housing in the one clutch half and is there provided with a detent arrangement which encloses the rear pin end with a spring arrangement whose end facing away from the other clutch half, on the one hand, is at least partially supported by the housing and, on the other hand, is supported at a collar of the coupling pin. One end of the spring arrangement is supported by way of a slide ring by a plurality of locking elements that are distributed around the circumference of the coupling pin and are captured between the slide ring, a cone envelope face of the coupling pin and an essentially radially oriented contact face of the housing.
Such detent arrangements are disclosed in European Patent No. 0,156,993 (which corresponds to U.S. Pat. No. 4,637,502), German Patent No. 3,602,282 (which corresponds to U.S. Pat. Nos. 4,798,559 and 4,838,829) as well as Unexamined Published German Patent Application DE-OS 3,720,301.
The coupling pin is here provided with a cone envelope face as support for the locking elements that are disposed on the side of the spring arrangement facing the other clutch half. With respect to the coupling pin, this cone envelope face extends radially outwardly toward the other clutch half. This type of structure produces the result that, if the coupling pin is displaced due to an overload, the locking elements are squeezed radially outwardly against the force of the spring arrangement until the coupling pin is able to pass within and through the then outwardly displaced locking elements with a movement that is directed away from the other clutch half. Thus a relatively large, so-called disengagement angle between the two clutch halves is connected with the prior art structure, that is, a rotation angle which lies between the coupling pin in the overload state and its engagement in the other clutch half, on the one hand, and the reaction in the sense of disengaging the clutch after the appropriate axial displacement of the coupling pin. That means that, in the prior art case, the clutch reacts only relatively slowly to the overload state in the sense of disengagement, with the friction forces generated with increasing load on the spring packet and acting between the locking elements and their contact at the slide ring, at the cone envelope face of the coupling pin and at the housing support playing a part here, in particular.